1. Field of the Invention
The present invention relates generally to the field of archery and, more specifically, to an improved bow design in which an internal acceleration system achieves a greater projectile launch speed than was previously possible.
2. Description of the Prior Art
The field of archery dates back to antiquity. Long bows, cross bows and today's multiple variety of compound bows are familiar items to a large segment of enthusiasts involved in sporting and hunting activities. The term “bow” is used herein to mean a “mechanical accelerating device for projectiles,” including hand bows for accelerating arrows in various forms including, for example, long bows, recurve bows, crossbows and compound bows used for accelerating arrows, bolts or balls as well as all other devices in which a projectile is accelerated with the aid of bows. Since the invention is intended to encompass various projectiles, such as arrows, bolts and balls, in the discussion which follows the terms “arrow” or “arrows”is often used alone but is intended to include all other suitable projectiles.
Modern crossbows now use sighting mechanisms of various sorts, but otherwise are little changed from antiquity, except in style and constructional materials. Draw weights are dramatically lower. A large medieval crossbow of circa 1500 AD might have a draw weight of 1200 lbs and a range of 450 yards. Today, a crossbow might not exceed 150 lbs draw weight. The basic elements are a short, horizontally mounted bow, a trigger mechanism (latch) to hold back the string, and the arrow which sits in a groove. Crossbows normally use rifle style stocks and the parts of the crossbow are often described in terms similar to those used to describe the parts of a rifle. Sights may be aperture sights as found on a rifle, pin sights as on a compound handbow, or telescopic sights. A modern 165 lb draw weight heavyweight crossbow will achieve similar projectile speeds to a 60 lb peak draw weight compound hand bow, and the bolt and arrow weights are also similar (30 gms). The crossbow, being relatively short compared to a vertical bow, will require comparatively more force to bend the bow.
While the traditional crossbow design has been around for hundreds of years, the basic design has certain inherent deficiencies. One of the major deficiencies is that the crossbow, as with the conventional bow, is limited in firing power by the maximum tension of which the bow is capable of achieving. It would be desirable to leverage the power of the conventional bow string to achieve an increase in the launch speed of the arrow or projectile being launched.
The present art is capable of achieving a launch speed on the order of 400 feet/second. An object of the present invention is to provide a powered bow capable of achieving launch speeds of 600 feet/second and greater.
These and other objects will be described more fully in the detailed description of the invention which follows.